Food product slicers having circular slicer knives are commonly used in restaurant and grocery businesses, among others. The use of slicer mounted knife sharpening assemblies to sharpen the peripheral edge of the slicer knife when necessary is also known. Many operators have difficulty determining when the slicer knife needs to be sharpened. The nature and extent of use of the slicer can vary widely, making the determination even more difficult. It would be desirable to provide a food product slicer that incorporates a feature that automatically identifies when the slicer knife should be sharpened.